The invention relates to electrostatic precipitators, including for diesel engine electrostatic crankcase ventilation systems for blowby gas for removing suspended particulate matter including oil droplets from the blowby gas.
Electrostatic precipitators, including for diesel engine electrostatic crankcase ventilation systems, are known in the prior art. In its simplest form, a high voltage corona discharge electrode is placed in the center of a grounded tube or canister providing an annular ground plane around the electrode. A high DC voltage, such as several thousand volts, e.g. 15 kV, on the center discharge electrode causes a corona discharge to develop between the discharge electrode and the interior surface of the tube providing a collector electrode. As the gas containing suspended particles flows between the discharge electrode and the collector electrode provided by the wall of the tube, the particles are electrically charged by the corona ions. The charged particles are then precipitated electrostatically by the electric field onto the interior surface of the collecting tube.
Electrostatic precipitators have been used in diesel engine crankcase ventilation systems for removing suspended particulate matter including oil droplets from the blowby gas, for example so that the blowby gas can be returned to the fresh air intake side of the diesel engine for further combustion, thus providing a blowby gas recirculation system.
In known electrostatic precipitators, the high voltage power supply is placed outside the collector section, either remotely mounted or mounted directly to the collector in some manner. In either of these configurations, a high voltage electrode rod or lead must pass-through an insulator section to deliver the high voltage to the corona producing discharge electrode assembly. The insulator may also be heated to prevent moisture and contaminant accumulation on the insulating surface, thereby reducing the insulating properties of such section.
The present invention eliminates the need for the noted high voltage pass-through of a high voltage lead through the noted insulator. In the present invention, the high voltage power supply is disposed internally of such insulator, and in the preferred embodiment is in the hollow interior of the corona discharge electrode assembly. This eliminates the need for any external high voltage cables or connections and eliminates the need for the high voltage pass-through of a high voltage lead through the insulator.
The present invention relates to improvements arising during continuing development efforts related to the subject matter of U.S. Pat. No. 6,221,136, incorporated herein by reference. The drawings and specification of the '136 patent are set forth below.